Heating system for refrigerator cars



c. D. N|VEN HEATING SYSTEM FOR REFRIGERATOR CARS Jan. 29, 1946.

Filed July 9, 1942 s Sheets-Sheet 1 .INVEIVITOR C HARLLS 0 /V/ Arrokvsys 1946. c. D. NlV EN HEATING SY STEM FOR REFRIGERATOR CARS FiledJuly 9, 1942 s Sheets-Sheet 2- Jan. 29, c D NlV HEATING SYSTEM FORREFRIGERATOR CARS Filed July 9, 1942 3 Sheets-Sheet 3 ATTORNEYSgrammatic showing the control Patented Jan. 29,1946

I HEATING SYSTEM FOR REFRIGERATOR CABS Charles David Niven, Ottawa.Ontario, Canada, alsignor to The Honorary Advisory Council for Ontario,Canada Application July 9, 1942, Serial No. 450,31 6

This invention relates to improvements in heating systems forrefrigerator cars of the type employing fuel heating means connected tocoils on the interior of the car through which heating liquid iscirculated. The objects of the invention -are to provide for moreeffective control of the temperature of the car through regulation ofthe circulating liquidand the heating means.

When refrigerator cars are used during cold weather it has been thepractice for some time to provide for some form of-heating means. In myUnited States Patent No. 2,076,961, dated April 13, 1937, a convenientform of such heating means has been illustrated. It is desirable,however,

that in such a device means should be provided" for controlling both thecirculation-of the heating fluid medium and the combustion of the solidfuel by means of which it is heated.

According to the present invention a thermostatic control is providedapplicable to trucks. railway cars and the-like, adapted for thetransportation of perishable products and equipped with fuel heatingmeans located below the floor of the car. In its construction theinvention comprises a double control consisting in the first place of athermostat located on the interior of the car and designed to controlthe flow of the liquid in the heating coil whereby a portion or all ofthe circulating liquid may be caused to flow through a suitable by-passpipe, and an auxiliary thermostat controlled by the temperature of theliquid in the by-pass pipe and adapted to control the solid fuel heatingmeans, means-in the form of a thermal trap or traps being preferablyprovided to prevent undesirable back circulation of the heating liquid,all as hereinafter more fully set forth and described in theaccompanying specification and drawings.

In the drawings:

Figure 1 is a diagrammatic top plan of a portion of a refrigerator carwith parts removed 7 showing the heating system installed therein.

Figure 2 is a sectional side elevation showin certain portions of thesystem.

.mgure 3 is a sectional elevation of a thermal trap employed in thesystem.

Figure 4 is a sectionalelevation partly diameans operated by the mainthermostat.

Figure 5 is a sectional elevation takenon the line 5-5 of Figure 4.

Figure 6 is a detail in elevation showing the link mechanism foroperating the draught control from the auxiliary thermostat.

Scientific and Industrial Research. Ottawa,

Figure 7 is a perspective detail of one of the contact members of thevalve.

Figure 8 is a section on the line 8-8 of Fi ure 4.

In the drawings like characters. of reference indicate corresponding.parts in all the figures.

Referring-to the drawings, A indicates a refrigerator car or truck,which may be of any convenient construction and "a portion only of 10which is shown.

B indicates a solid fuel heater, conveniently located beneath the floorIt of the-car and which may beof any convenient design, such as thatshown in my aforesaid Patent No. 2,076,961,

the combustion in the heater being adapted to be controlled by asuitable damper H of any con-- venient design.

C indicates the heating coll connected in series with. the heater andthrough which heating liduid is circulated, this heating liquid beingpreferably a suitable antifreeze solution. The pipes C are suitablyconnected to'fiuid heating means forming part of the heater B, and thecoils C are suitably arranged on the interior of the car to effect thedesired heating thereof, the direction of flow of the liquid through thecoil C being indicated by arrows. The heater B may be convenientlyheated by charcoal contained in the usual firepot in the heater andsupplied from a suitable hopper, as set forth'in my earlier patent.

D indicates the main controlling thermostat, which is situated insidethecar, preferably under the floor racks i2. It may be of any convenientdesign, that illustrated including a large bimetal- 86 he coil l3.

The thermostat D is designed to control a valve E, the construction ofwhich is shown'in detail in Figures 4, 5, 7 and 8. I'his valve includesa casing It, the lower part of which is connected 40 to the riser pipe15 which should be therznall insulated or lagged and which forms part ofthe circulating coil system C, and alternative outlet pipes l6 and H,the pipe I! forming part of the usual circulating system of the heatingcoils on- I the interior of the car, while the pipe 16 constitutes aby-pass for the return of the heatin fluid medium when the usual or maincirculation is closed as hereinafter described. This by-pass ipe I!should be thermally insulated to prevent its heating up the car.

The function of the valveE is to direct the to should move with aslittle power as possible, and

in the embodiment illustrated it is constructed with a pivoted flapmember l8 adapted to carry contact members l9 and 20 on opposite sidesdesigned to control the outlet from the casing to the pipes H or H. Tofacilitate the control, conical reducing members 2| and 22 are providedon the ends of the pipes 16 andll having screw threaded or othersuitable engagement with the ends of these pipes. The opening ends ofthese conical reducing pieces maybe quite small in diameter, say of theorder of half an inch, and they are carefully machined to fit thecontact members l9 and 20.

Each of the contact members 19 and 20 includes a triangular plate 23loosely mounted on transverse posts 24 supported on the plate l8, whichis fixed to and turns with the shaft 25, and which is suitablyjournalled in the casing I4. Springs 26 surround the posts 24 on .eachside and hold the plates 23 in their outermost position against nuts 21.The plates 23 at the outer side carry contact pieces 28 of brass. Byadjusting the nuts 21 the position of the contact plates 23 maybeadjusted accurately so as to close exactly over one or other of theconical members 2| and 22. v

The plate I8.which constitutes the flap of the valve, is accuratelybalanced and designed to be moved from the thermostat by suitable linkmechanism. In .the form of this mechanism illustrated the end of theshaft is provided with a crank 29, the outer end of which has slidingengagement with the end ,of a lever 30, mounted in a tubular extension32 supported on the casing M. The opposite end of the lever 30 isconnected through a coupling 3| to the end of the bimetallic coil l3 onthe thermostat. The bimetallic coil l3 as it expands or contracts isadapted to move the lever 30 in a direction substantially at rightangles to its axis, as indicated by the arrows in Figure 4. T0 guidethis move:- ment and prevent excess movement stops 31a may be providedon the coupling 3| co-operating with corresponding spaced stops 3lbprovided on a suitable base plate 3lc, which maybe conven ientlyconnected to the floor of the car.

In order to permit free movement of the arm A of the lever 30 and toprevent escape of the heatthreaded adapter 34 to the extension 32 andhaving at its outer'end a connector 35 which is fastened to the lever30. In this way the increas or reduction in curvature of the bimetallicc of the thermostat D is caused through the lever 30 and crank 29 tooperate the flap plate I8 moving it into alternative positions in whichone or other of the pipes 16 or H is closed or to some intermediateposition in which the outlets to both p pes are open. 7 Y In order toprevent the circulation of a random v nature inside the pipe when theinlet to the main for adjusting the thermostat D from the exterior ofthe car. The means which I have illustrated for this purpose include arod 3'! connected to pivoted arm 38 on the thermostat and designed toeffect slight winding or unwinding of the coil l3, the outer end of therod having screw threaded engagementwith a sleeve 39, the sleeve beingrotatively mounted in a suitable support 40, and

being designed to be turned in its support by means of a rod 4! having acrank 42 at its outer extremity mounted in a suitable control box 43.The liquid passing into the by-pass pipe I6 is designed to be returnedto the heater B through coils 44 and 44a leading to a connecting T 45which joins with the return pipe 46 which should be thermally insulatedor lagged and which is part of the main circulating system. The main andby-pass pipes thus meet at the T 45, and in order to prevent randomcirculation adjacent to this point a thermal trap 41 having a similarconstruction to the trap F as shown in Figure 3 but with the prong ordam extending upwardly is provided in the coil 44 adjacent to the T 45.It will be observed by reference to Figure 2 that the relatively longpipe legs 41a and'flb are provided on opposite sides of the trap 41 sothat the fluid is caused to pass upwardly to and through Q the trap andthen downwardly.

G indicates the auxiliary thermostat. connected to the by-pass pipe ISin such a way that it will be affected by the temperature of the liquidpassing therethrough, this thermostat being operatively connected to thedamper I I. The thermostat G may be of any convenient design, preferablyincluding a bimetallic coil which, when heated by the hot liquid passingthrough the 'by-pass, will be moved with sufficient power to operate thedraught control 'II and may be pro-' tectively surrounded by a metalbox. The convenient form of connection is illustrated in which the arm43 connected to the end of the thermostat passes through and has looseengagement with a lever 49 which is pivoted intermediate of means of aspring 55 fastened at one end'to the me is closed a thermal trap F isinserted in the pipe 11 adjacent to the valve E, Thistrap F, whichmay beof a form shown in Figure 3, is formed with a baiiie member 36 extendingfrom the-top of the trap downwardly and designed to prevent the hotliquid from travelling along the with the upper end of the lever 49. Thespring operating the thermostat G moving the damper 52 and 53. thelatter stop having arranged at its inner face a pivoted contact piece 54which -may be swung out of engaged position as indicated in dotted linesin Figure 6. Thiscontact piece 54 will normally liein position over theend of the stop 53 s6 that movement of the lever will be limited on oneside by the stop 52 and on the other side by the contact member 54. Whenit is desired to cut off the 'fire completely, however, the contactpiece 54 is swung upwardly and the lower end of the lever is movedagainst the stop a 53 as'shown in dotted line in Figure 6. The lever maybe conveniently held in this position by 1 plate 50 and designed to be'releasably engaged 55 should be strong enough to overcome any tendencyof the thermostat to move it due to cooling.

It will thus be seen that when the main thermostat E moves on account ofthe car being too warm, it closes off the circulation in the maincirculating pipe ll. This directs the heated liquid into the by-passpipe l8, which then heats up,

control ll, which in turn reduces the firein the heater B. when the carcools the reverse of these operations takes place. v

is an automatic control both of the amount of liquid circulated inthe=car and of the heating means.

The position of the thermal traps F and 41 has an important effect onthe control of the circulating medium. The trap F should be locatedbeyond the riser pipe IS in the usual circulation of the heating mediumand also beyond the valve E which is conveniently placed at the pointwhere the usual circulating pipe emerges from the thermally insulatedbox around E. It will be found 'liquid circulation while the trap 41prevents random cold liquid circulation.

What I claim as my invention is: l. A heating system for refrigeratorcars comprising in combination circulating coils extending in theinterior of the car, heating means located outside the car, a connectionadapted to feed a heating medium from the heating means to one end ofthe coils and a connection adapted to carry the return from the otherend of the coils back to the heating means, a by-pass pipe engage theports at the correct angle to completely close the same.

3. A heating system for refrigerator cars com-. prising in combinationcirculating coils extending in the interior of the car, heating meanslocated outside the car, a connection adapted to 7 feed a heating mediumfrom the heating means adapted to receive heating medium diverted fromthe coils and return it tothe heating means for recirculation, saidby-pass pipe having a portion extending on the exterior of the car bywhich heat may be dissipated, valve means adapted to be positioned bythermostatic means responsive to the temperature inside the car to closeofl access of the heating medium either to the bypass pipe whereby theheating medium is circulated'through the coils to return, orto close of!access -to the coilswhereby the heating medium is diverted to theby-pass pipe and returned to the heating means for recirculation.

2. A heating system for refrigerator cars comprising in combinationcirculating coils extending in the interior of the car, heating meanslocated outside the car, a connection adapted to feed a heating mediumfrom the heating means to one end of the coils and a connection adaptedto carry the return from the other end of the coils back to the heatingmeans, a by-pass pipe-adapted to receive heating medium diverted fromthe coils and return it to the heating means for recirculation, saidby-pass pipe having a portion extending on the exterior of the car bywhich heat may be dissipated, valve means adapted to be positioned by'thermostatic means responsive to the temperato one end of the coils and aconnection adapted to carry the return from the other end of the coilsback to the heating means, a by-pass pipe adapted to receive heatingmedium diverted from the 'coils and return it to the heating means forrecirculation, said by-pass pipe having a portion extending on theexterior of the car by which heat may be dissipated, valve means adaptedto be positioned by thermostatic means responsive to the temperatureinside the car to closeoff access of the heating medium either to thebypass pipe whereby the heating-medium is circulated through the coilsto return, or to close oil access to the coils whereby the heatingmedium is diverted to the by-pass pipe and returned to the heating meansfor recirculation, said valve means comprising a casing having an inletfor the heatingmedium, an outlet port leading to the heating coils, andan outlet port leading to said by-pass pipe, both of said ports havingcon-I members at the correct angle to completely close the respectiveports.

4. A heating system for refrigerator cars comprising in combinationcirculating coils extending in the interior of the car, heating meanslocated outside the car, a connection adapted to feed a heating mediumfrom the heating means to one end of the coils and a connection adaptedcoils and return it to the heating means for reand a flap valve memberswingable by the ther- 7 mostatic means to close one or other of theports,

the valve memberhaving adjustable spring-supported contact piecesadapted automatically to to carry the return from the other end of thecoils back to the heating means, a by-pass pipe adapted to receiveheating medium diverted from the coils and return it to the heatingmeans for recirculation, said by-pass pipe having a portion extending onthe exterior of the car by which heat may 'be dissipated, thermostaticmeans responsive to the temperature inside the car-adapted to controlmechanically the flow of. the heating medium by either directingthe'heating medium to the coils in the interior of the car and thenceback to the heating means, or diverting the heating medium from-thecoils to the by-pass pipe to be returned to .t e heating means forrecirculae tion, andan auxiliary thermostat responsive to thetemperature of heating 'medium in the bypass pipe adapted, according tothe temperature of such heating medium, to eifect control of thecombustion oi fuelin said heating means.

5. A heating system for refrigerator cars comprising in combinationcirculating coils extending in the interior of the car, heating meanslocated outside the car, a connection adapted to feed a heating mediumfrom the heating means to one is end of the coils and a connectionadaptedto carry the return from the other end of the coils back'tothe'heating means, a by-pass pipe adapt-- ed to receive heating mediumdiverted from the circulation, said by-pass 'pipe having a portionextendingon the exterior of the car by which heat may be dissipated,thermostatic means responsive to the temperature inside the caradaptedto control mechanically the flow oi. the heating medium by eitherdirecting the heating medium to the coils in the interior of the car andthenceback to the heating means, or diverting the heating medium fromthe coils to the by-pass pipe to be returned to the heating means forrecirculation, an auxiliary thermostat responsive to the temperature ofheating medium in the by-pass pipe adapted, according to the temperatureof such heating medium, to effect control of the combustion of fuel insaid heating means,

a damper for said heating means, link mechanism.

between the second thermostat and the damper, and regulatable meansadapted to limit movement of said linkmechanism beyond a predeterminedpoint set to maintain a predetermined minimum opening on which the firemay be kept alive, said means being removable for complete closure ofthe damper as desired.

6. A heating system for refrigerator cars com prising in combinationcirculating coils extending in the interior of the car and including anapproximately horizontal portion, a heater located outside the car, aconnection adapted to feed heating liquid from the heater to one end ofthe coils and a connection adapted to receive the return from the otherend of the coils and carry it back to the heater for recirculation, aby-pass Y pipe adapted to receive heating liquid diverted,

from the coils and return it to the heater for recirculation, saidby-pass pipe' having a portion extending on the exterior of the car bywhich heat may be dissipated, valve means adapted to be positioned bythermostatic means responsive to temperature inside the car to close'011 access of ing in the interior of the car and including atapproximately horizontal portion, a heater located outside the car, aconnection adapted to feed heating liquid from the heater to one end ofthe coilsand. a connection adaptedto receive the return from the otherend of. the coils and carry it back to the heater for recirculation, aby-pass pipe adapted to receive heating liquid diverted from the coilsand return it to the heater for recirculation, said by-pass pipe havinga portion extending on the exterior of the car by which jacent to saidvalve and adapted to prevent the hot liquid from travelling along thetop of the pipe andthe cold liquid returning along the bot- .tom to takeits place sa id trap comprising a passageway for the heating liquid anda baflle member extending from one side of the passageway the heatingliquid either to said by-pass pipe whereby the liquid is circulatedthrough the coils to return, or to close 0115 access to said coilswhereby the heating liquid is diverted to thebypass pipe and returned tothe heating means for recirculation, and a thermal trap arranged in theapproximately horizontal portion of the coils adjacent to'said valve.and adapted to prevent the hot liquid from travelling along the top ofthe pipe and the cold liquid'returning along the bot-' tom totake itsplace;

'7. Aheating system ior refrigerator carscomprising in combinationcirculating coils extendtowards the opposite side and defining with suchopposite side a restricted passageway of a depth which is a smallproportion of the total height of liquid in the immediately adjacentportions of the circulatingcoils,

8. A heating system as defined in claim 7 in which the by-pass pipeincludes an approximately horizontal portion, and a thermal trap in theflow in such portion adapted to prevent hot liquid travelling along thetop of the by-pass pipe and Q cold liquid returning along. the bottom totake its place,. said trap comprising a passageway for the heatingliquid and a baffle member extending from one side of the passagewaytowards the opposite side and defining with such opposite side arestricted passageway of a depth which is a small porportion of thetotalheight of liquid in CHARLES DAVID NIVEN.

the adjacent portions of the by-pass pipe.

